Elbow arthroplasty replacement research methods, outcome domains and instruments in clinical outcome studies: a scoping review

Aim Prosthetic joint replacement of the elbow including total elbow replacement, hemireplacement, radial head replacement and radiocapitellar replacement, are rare procedures. This scoping review aims to map current research to inform the development of future research. Materials and Methods A scoping review was undertaken adhering to the Joanna Briggs Institute (JBI) guidelines using Medline, Embase, CENTRAL and trial registries limited to studies published between 1st January 1990 and 7th February 2021. Endnote software was used for screening and selection and was limited to randomised trials, non-randomised controlled trials, prospective and retrospective cohort studies, case-control studies, analytical cross-sectional studies and case series of ten patients or more reporting clinical outcomes of elbow replacement. The results are presented as frequency counts of types of studies reported, sample size, length of follow up, clinical outcome domains and instruments used, funding sources and a narrative review. Results 362 studies met the inclusion criteria. The majority were of total elbow replacement (246, 68%), followed by radial head replacement (100, 28%), distal humerus hemireplacement (11, 3%) and radiocapitellar replacement (5, 1%). Most studies were retrospective (326, 90%) and most were observational (315, 87%). The median study sample size for all implant types across all studies was 36 implants. The median length of follow up for all study types was 56 months. A total of 583 unique outcome descriptors were used that were categorised into 18 domains. A total of 105 outcome instruments were used to measure 39 outcomes. Discussion This review has found the majority of published research into elbow replacement consists of retrospective observational studies with small sample sizes and short follow up. A large number of outcome descriptors were used with a high number of different outcome instruments employed indicating a need to define a core outcome set for elbow replacement. Key words: Arthroplasty, Replacement, Elbow, Outcome, Methods, Funding Page 1 of 4